1. Field of the Invention
The present invention relates generally to a portable liquid oxygen unit.
2. Description of the Background Art
Therapeutic oxygen is the delivery of substantially pure oxygen to a patient in order to facilitate breathing. When a patient suffers from pulmonary/respiratory problems, delivery of oxygen helps the patient get an adequate level of oxygen into his or her bloodstream.
Therapeutic oxygen may be warranted in cases where a patient suffers from a loss of lung capacity. Medical conditions that may make oxygen necessary are chronic obstructive pulmonary disease (COPD), including asthma, emphysema, etc., as well as cystic fibrosis, lung cancer, lung injuries, and cardiovascular diseases, for example.
Related art practice has been to provide portable oxygen in two ways. In a first approach, compressed oxygen gas is provided in a pressure bottle, and the gas is output through a pressure regulator and a hose to the nostrils of the patient. The bottle is often wheeled so that the patient may be mobile. The drawback of compressed, gaseous oxygen is that a full charge of a bottle that is portable does not last very long.
In order to get around this limitation, in a second approach a related art liquid oxygen (LOX) apparatus has been used wherein LOX is stored in a container and the gaseous oxygen that evaporates from the LOX is inhaled by the patient.
The related art LOX apparatus enjoys a longer usable charge than the compressed gas apparatus for a given size and weight, but has its own drawbacks. LOX, being a liquid that is very cold, requires a vacuum-insulated container.
Related art portable LOX units typically are formed with necks that can fill with LOX when tipped, and thus are to be used and carried only in a generally vertical position. This can be impractical at times, such as when driving a vehicle, for example. A vertically positioned related art portable LOX unit is unstable and could potentially cause problems for both the oxygen user and for other drivers if it shifts, slides, or tumbles.
There remains a need in the art, therefore, for an improved portable LOX unit.